CHAPTEK II 

 18441849 



PASTEUR often spent his leisure moments in the library of 

 the Ecole Norm ale. Those who knew him at that time remem- 

 ber him as grave, quiet, almost shy. But under these reflec- 

 tive characteristics lay the latent fire of enthusiasm. The 

 lives of illustrious men, of great scientists, of great patriots 

 inspired him with a generous ardour. To this ardour he added 

 a great eagerness of mind ; whether studying a book, even a 

 commonplace one for he was so conscientious that he did not 

 even know what it was to " skim " through a book or coming 

 away from one of J. B. Dumas' lectures, or writing his 

 student's notes in his small fine handwriting, hafwas always 

 thirsting to learn more, to devote himself to great researches. 

 There seemed to him no better way of spending a holiday than 

 to be shut up all Sunday afternoon at the Sorbonne laboratory 

 or coaxing a private lesson from the celebrated Barruel, Dumas' 

 curator. 



Chappuis anxious to obey the injunctions of Pasteur's 

 father, who in every letter repeated " Do not let him work 

 too much ! " desirous also of enjoying a few hours' outing with 

 his friend used to wait philosophically, sitting on a laboratory 

 stool, until the experiments were over. Conquered by this 

 patient attitude and reproachful silence Pasteur would take off 

 his apron, saying half angrily, half gratefully, " Well, let us go 

 for a walk." And, when they were out in the street, the same 

 serious subjects of conversation would inevitably crop up 

 classes, lectures, readings, etc. 



One day, in the course of those long talks in the gardens of 

 the Luxembourg, Pasteur carried Chappuis with him very far 

 away from philosophy. He began to talk of tartaric acid and 

 of paratartaric acid. The former had been known since 1770, 

 thanks to the Swedish chemist Scheele, who discovered it in 



